1. Technical Field
The present invention relates generally to rolls of the type used in roller conveyors and, more particularly, to a roll assembly having a replaceable roll covering.
2. Discussion
As is known, roller conveyors are used in material handling systems for moving objects from one location to another. Conventional roller conveyors include a series of rolls that are rotatably supported from a rigid frame structure. Typically, the rolls have an elongated cylindrical body segment which is mounted between a pair of frame rails. The cylindrical body segment of the roll can be journalled on a support shaft extending between the frame rails or, in the alternative, can have integral end shafts that are supported in anti-friction bearings mounted in the frame rails. Regardless of the roll type, it is also known to provide a layer of a cover material (i.e., rubber, urethane, etc.) on the outer surface of the cylindrical body segment. The cover layer functions to minimize potential damage to the objects caused by contact with the rolls while concurrently assisting in the frictional movement of the objects on the rolls. Irrespective of the type of material used for the cover layer, its outermost contact surface will ultimately wear and thus necessitate replacement of the roll from the conveyor. Once the roll is removed from the conveyor it is either discarded or refurbished by stripping the old cover layer and subsequently bonding a new cover layer on the roll. As is obvious, this refurbishing process is both labor intensive and expensive.
In an effort to minimize the costs associated with replacing and/or repairing worn-out rolls, it has previously been proposed to install a replaceable cover strip on the body segment of the roll. Typically, hook and loop materials, such as Velcro(copyright), and other analogous latch-type fastener products, have been used to releasably secure the cover strip to the body segment of the roll. In such arrangements, a mounting strip is permanently secured to the outer surface of the roll""s body segment and is adapted to receive the replaceable cover strip to which the cover layer is bonded. However, these releasable latch-type mounting arrangements have proven to have limited functional utility. In particular, since the contact interface defined between the interdigitated latching projections on the mounting strip and the cover strip is irregular and of low density, the weight of the objects supported on the rolls may tend to cause undesirable radial and/or circumferential deformation of the cover strip. Thus, a need exists to develop an improved roll covering, and a method for installing and replacing the roll covering on a conveyor roll, which overcomes the shortcomings of the prior art.
Accordingly, it is an object of the present invention to provide a roll assembly comprised of a roll, a carrier strip adapted to be secured to the roll, and a replaceable cover strip adapted to be adhesively bonded to the carrier strip. When it is desired to remove the cover strip from the roll assembly, the cover strip is stripped from the carrier strip such that the adhesive causes a portion of the carrier strip to be pulled away with the cover strip. As such, the newly exposed surface of the carrier strip is then prepared to have a replacement cover strip adhesively bonded thereto.
A related object of the present invention is to provide a replaceable cover strip for the roll assembly which includes a substrate layer having an inner surface adapted to be adhesively bonded to the carrier strip, and an outer surface to which a cover layer is bonded.
As a further object, the cover strip for the roll assembly of the present invention includes an adhesive layer having an inner surface bonded to the inner surface of the substrate layer and an outer surface capable of being activated for bonding to the carrier strip.
It is a further object to provide a carrier strip for the roll assembly of the present invention which includes a base layer having an inner surface adapted to be adhesively bonded to the outer surface of the roll, and an outer surface to which the base layer of the cover strip is adhesively bonded.
As a related object, the base layer of the carrier strip is made from a friable and/or peelable material that will release (i.e., slough-off or shed) a thin skin portion of the friable material in response to delaminating the adhesive bond between the adhesive layer of the cover strip and the base layer of the carrier strip.
As a further object, the adhesive bond between the roll and the carrier strip has greater strength than the adhesive bond between the cover strip and the carrier strip to permit removal of the cover strip from the roll when replacement is required.
Accordingly, the roll assembly of the present invention provides a replaceable roll covering for rolls used in roller conveyors and is further directed to methods of installing and removing the replaceable roll covering.